Electrical pickup for string instruments



Jan. 8, 1952 E, GRlMsHAw 2,581.653

ELECTRICAL PICKUP FOR STRING INSTRUMENTS Filed 0G15. 29. 1948 Patented Jan. 8, 1,952

(1F-FI CE.

ELnrnIcAL yPICKUP Fon STRING, INS.rRUMEsTSA Emile Grimshaw, London, England Applicationoctoher 29, 1948, Serial No. 57,263l

Igfretrifain Naveelber 1.04.9117

This invention relates-to musical instruments in combination with. electricv pick-ups, particularly to banjos, guitars, and instruments ofthis nature.

Musical instruments of the. kind to which the invention isvapplied comprise, as iswell known, a body and a neck.

Among objects ofthe inventionare -toprovide a. combination of musicalinstrument of the kind referred to above and electrical pick-up which shallbe simple tormanufacture, employ a minimum number of parts, is simple to assemble and adjust, and which shall require no or very little alteration in the construction of the musical instrument.

TheV invention will bebetter understood by reference to the accompanyingdrawingwherein Figurel is a face viewrof a guitar incorporating an electric pick-up, Figure 2 is a section of the pick-up, taken` alongits medial axis, and, Figure3 is a detail.

Referring to Figurevl, thebodyofthe guitar is indicated generally by reference` I, andthe neck, the upper end of which is not shown, by reference 2. At 3 is indicated a guard situated alongside and substantially coplanar with the strings 30.

Usually, the neckzwould end` at 4. For the purpose of my invention, however, the neck is extended by the memberti,y which4 maybe integral with the neck or, as shown.may,bethefupper surface of abox-likecover member 6,- as better seen innFigure 2.

The cover member 6 consists of theA upper member 5, already mentioned, an end member l, and side memberswhich cannot be seeninthe drawings, but Whoseplanes are parallel with the plane of Figure 2. The other end 8 of the cover member 6 is open as is also the lower part 9. The end of the neck is recessed as at IU.

By means of a screw II, the cover member 6 can be secured to the front l2 of the body of the instrument, whereby a hollow cavity I3, in part enclosed by cover member 6 and in part by the recess I is provided.

Cavity I3 accommodates a coil I4 surrounding a slab magnet I whose poles are respectively at the ends I8 and Il. End I6 is provided with a soft-iron yoke I8 of right-angular cross section, as may be seen from Figure 2.

The length of the yoke, in the direction across the Width of the neck is somewhat greater than the distance between the two outer wires 30 of the instrument, and the horizontal member I9 of the yoke is provided with a number of screw threaded holes I9, see Figure 3. The number of 2A holes I9 and' their distancek apart will depend upon the kind of -stringedinstrument to. which the invention is applied; The guitar. illustrated in Figure 1 has six strings, and so yoke. Iii w-ill have six holes.

Each hole I9r accommodates a screw-threaded soft-iron stud 20.

A damping member. 2 I of, forl examplev rubber, is situated between pole-end il `oftheeslab `magnet, and the end of the,4 neck ofthe instrument at 22. Also a strip 2.3oi insulating material is interposed between the ends'ofthe studs 2B and the front I2 of the instrument.

The upper member -5IofV the covermember 5 is provided with a number of holes 2d, see Figure 2. The number of holes-,and their situations and distance apartcorrespond with the number, Situations,r and distance aparto studs 2i! so that when thev parts are assembled inthe manner shown in Figures 1 and 2, the heads. ofthe studs extend into holes 24.

Cover member 6 is attached to the body of th instrument by means of` screw Il, in such manner that each stud 20 is situated under a differen t string.

Guard v3 isper senofpart of my invention; it is provided, as isV known, to protect the body of the instrumentjfrom scratchingwhen the instrumentis being played: However, as an auxiliary feature of my invention, Imakeuse of Ithis guard for the accommodation of volume and tonecontrols 26 and other incidental membersrsuch as condenser 21.

Coill I4 is connected-by-wires-AN to the controls 26, and a jack-29- serves-.as a means for connecting the output Vof the'pick-upito a loud speaker through any amplifying. system that may. be necessary or desirable.

Adjustment of the distances between the pole pieces of the magnet and the strings can be effected by screwing the studs 20 into or out oi' yoke I8, for which purpose the heads 25 of the studs are provided with saw-cuts, as at 3|.

While I have shown and described a pick-up device in which there is a separate pole piece for each string, it is, of course, obvious that a pole piece may serve more than one string, suitable readjustments being made in the spacing of the holes I9 and 24 and size and shape of the studs; indeed a single pole piece may serve all the strings, in which case a single elongated aperture may be provided in member 5.

While I have shown and described a particular construction of instrument and pick-up, it is apparent that modifications may be made Within the spirit and scope of the appended claims.

2. A stringed musical instrument of thekind having a body part and a neck in combination with an electric pick-up comprisinga recess in the end of the neck adjacentto. the body, a box-f 5. A stringed musical instrument of the kind having a body part and a neck in combination with an electric pick-up comprising a. recess in the end of the neck adjacent to the body, a coil accommodated in the recess, a magnet surn rounded by the coil, a plurality of pole pieces for'themagnet each adjacent to'a wire of said instrument, a guard plate adjacent the neck of the instrument, control means attached to the guard situated between the guard and the body .of the instrument, connections between said coil --and said controls, a jack for outside connections attached to the guard situated between the guard andthe body of the instrument, and conlike cover member, an upper member fonthe y.

box-like member having an upper surface forming a continuation of the ngering surface Yof the neck, a cavity formed partly by said recess and partly by said box-like cover member. lan

aperture in said upper member,r an electric pick-up device within saidcavity, and a magnetic pole piece for said pick-up device, said pole piece extending through said aperture and having its end adjacent toa wire of the instrument. l

3. A stringed musical instrument of the kind having a body part and a neck in combination with an electric pick-up comprising a recess in the end of the neck adjacent to the body, a boxlike cover member, an upper member for the boxlike member having an upper surface forming a continuation of the lingering surface of the neck, a cavity formed partly by said recess and each said pole piece extendingA through one of said apertures and having its end adjacent to a wire of the instrument.-

4. A pick-up device for a stringed musical instrument having a body part and a neck, com- A prising within a cavity at the end of the neck adjacent to the instrument. said cavity situated under the strings of the instrument, a coil within said cavity, a magnet surrounded by said coil,

nections between the controls and jack.

6. Apick-up device for a stringed musical instrument having a body part and a neck, comf prisingwithin a cavity at the end ofr the neck a magnetic angular yoke for said magnet, a plusaid aperture, a cover member coplanar with the iinger board oi said neck, a plurality of aper- ,A

tures in said cover member, each said stud extending into an aperture in said cover member.

adjacent to the instrument, said cavity situated under the strings of the instrument, a'coil within said cavity, a magnet surrounded by said coil, a magnetic angular yoke for said magnet, a plurality of screw-threaded apertures in one member of said yoke, a like plurality of screw threaded studs serving as pole-pieces one screwed into each said aperture, a cover member coplanar with the iinger board of 'said neck, a plurality of apertures in said cover member, each said stud extending into an aperture in said cover mem@ ber, a ,guard plate adjacent the neck of the instrument, control means attached to the guard situated between the guard and the body of the instrument, connections between said coil and said controls, a jack for outside connections attached to the guard situated between the guard and the body of the instrument, and connections between the controls and jack. 7. A musical instrument as set forth in claim 3 including an electric system for said pick-up device, volume and tone control devices, and connections connecting said pick-up device to said controls.

' EMILE GRIMSHAW.4

REFERENCES CITED The following references are of record in the le of this patent:

` UNITED STATES PATENTS Number Name Date `2,087,106 Hart July 13, 1937 2,145,490 Miller Jan. 31, 1939 2,236,946 Knopp l Apr. 1, 1941 

